In this remarkable book, Duncan Watts, one of the principal architects of the new science of networks, lays out nothing less than a new way to understand our connected planet. Between the Internet and e-mail, cell phones and satellites, friends and family, highways and airports, we are continuously surrounded by and subjected to a world of networks -- often bewilderingly so. Whether they bind computers, economies, or terrorist organizations, networks are everywhere in the real world, yet until recently the fundamental nature of the networks themselves has remained shrouded in mystery. However, in the past few years, Watts and others have spearheaded a new generation of research that is rapidly revealing the rules by which networks grow, the patterns they form, and the way in which they drive collective behavior. From epidemics of disease to outbreaks of market madness, from people searching for information to firms surviving crisis and change, from the structure of personal relationships to the technological and social choices of entire societies, Watts weaves together a network of discoveries across the academic spectrum, from physics to sociology, to tell the story of an explosive new science, the people who are building it, and his own peculiar path through it all.